Three Veterans Cooperative trials evaluating antiepileptic drug (AED) therapy in the elderly demonstrated that the ability to tolerate the AED is a more determining factor for long term success than the ability to suppress seizure activity. In general, elderly patients appear more intolerable to medications. This may stem from co-morbid conditions, concurrent medications, pharmacokinetic changes, and/or pharmacodynamic changes. Therefore, it is important to study the efficacy and tolerability of AEDs in the elderly.